The effect of pH on citric acid cough challenge: A randomised control trial in chronic cough and healthy volunteers

Citric acid has been used for over six decades to induce cough; however the mechanism of its pro-tussive effect is still not fully understood. We assessed the response to inhalation of citric acid at varying levels of acidity to determine if the pH of the solution plays a role in the induction of cough. Data was collected from both healthy volunteers and patients with chronic cough.20 chronic cough patients and 20 healthy volunteers were...